Heat engine



July 3, 1928. 1,675,829

H. 4F. SMITH HEAT ENGINE Filed April 2, 1923 2 Sheets-Sheet 2 Patented July 3, 1928.

UNITED STATES y' 1,615,829 PATENT OFFICE.

HARRY F. SMITH, OF DAYTOILOHIO, ASSIGNOR T0 THE GAS RESEARCH COMPANY, OF DAYTON, OHIO, A CORPORATION 0F OHIO.

HEAT ENGINE.

Application led April 2,

This invention relates generally to a new and improved method of, and apparatus for, transferringheat energy, and more particularly to an improved form of heat engine, of the so called hot aii"type, constructed to operate in accordance with such method.

One of the principal objects of this 1n- Vention is to provide a new and improved method of heat transfer, and 'apparatus for carryingthat method into effect.

Another object of this invention is to .provide an improved form of heat engine, which is simple in construction, eiiicient and reliable in operation, and of such character r that it requires substantially no attention during operation.

Other objects and advantages 0f the 1nvention will be apparent from the description thereof when taken in connection with the accompanying drawing. 0

This invention is a continuation 1n part of the application of Harry F. Smith, Serial No. 488,674 filed Julyv 30, 1921.

In the drawing in which like characters of reference designate like parts throughout the several views thereof:

Fig. 1 is a vertical sectional view through a combined motor and pump embodying this invention, and constructed to carry on Athe new method of heat transfer;

Fig. 2 is a sectional view throughthe en- I gine and pumpshown in Fig. l, the section being taken along a plane at ,right angles to the plane 'of Fig. l;

F ig. 3 is a view particularly adapted to show the construction of the refrigerator forming a part of the engine in Figs. l and 2, the view being along the line 3-3 of Fig.` 4E;

Fig. 4- is a sectional view along the line 4 4 of Fig. 3;

Fig. 5 is a view, in the nature of a per spective, of a part of the apparatus;

\ Fig. 6- is a fragmentary 'sectional view of a slightly modified form of the invention;v

and l Fig. 7is avertical sectionalview through an engine of similar type, the engine being constructed to operate in the reverse position and without the pump element'directly connected thereto.

In the drawing is shown a, type of ,engine particularly designed for operating upon the heat generated by the burning of some comprises a. water j acketed cylinder 20, cooling water being supplied to the cylinder jacket through the pipe 21 andled off from the cylinder jacket through the pipe 22. These two pipes are preferably connected to a hot water storage tank, such as is ordinarily provided for household use, this tank .not being shown. Connected to one end of the cylinder 20 is a member 23, consisting of some material which is highly resistant to heat, and is also a good radiator of heat. Preferably this member is composed of ysome one of the well known nickel-chro mium heat-resisting alloys, such as the material known commercially as Q-metal.

Mounted upon the other end ofthe cylinder 20 is a plate 25, having a central opening or hole 26 therein, within which is positioned the piston 27. This piston has, on the end which extendsl into the cylinder 20, an extension 28. The other end of the piston is hollow, or cup shaped, and is surattached to the free end of the piston. This sylphon is so attached to the vpiston and to the plate 25 that a gas tight jointis secured at each place of attachment. Since the sylphon readily expands and collapses, reciprocation of the piston within the cylinder is permitted while at the same time leakage along the piston is'prevented without the use of ordinary packing which,A in order to insureI a gas tight fit, produces excessive friction thus decreasing mechanical efiiciency. Obviously in an. engine ofthe type described, the cylinder containing the expansible fluid must be tight, under the pressure attained, otherwise the efliciency of the device will be materially affected. With the type of oQnStruGOIl llt/re d CSClbd.

' hold them in properly assembled The face of the cap 51 is provided with suit-Ak leakage is preventedl while at the same time friction losses are minimized, and substan tially prevented.

Passing through a suitable opening in the side of the cylinder 20 is a sleeve 35 constructed to receive a crank shaft 36, the inner end of which is enlarged, as shown at 37, to form a crank disc, a labyrinth packing 38 being provided between the end of the sleeve 35 and the cooperating facel ofthe disc 37, to prevent leakage. Connected to the disc 37 but spaced therefrom a suitable distance by means of the eccentrically arranged crank pin 39, is a second crank disc 40, which preferably corresponds in diameter with the disc 37. Connected to the disc 40, and eccentrically arranged With respect thereto is an extension orcrank-pin 4l, the pins 39 and 41 being arranged so that during operation of the engine the crank-pin 39 is substantially 90O in advance of the crank-pin 4l. The shaft 36 is supported within suitable ball-bearings 45. A sleeve 46 surrounds the shaft, and serves to properly space the ball-bearings 45. This sleeve is surroundedby a cage 47, which fits Within the bore of the sleeve 35, the cage and the wall of the sleeve being cut away, as at 48, to permit the free passage of lubiicant from the rease cup or lubricator 49 to the interior o the combined bearing and packing. A cap 51 is provided for the sleeve 35, which contacts with the outer ball-bearing and the outer end of the cage 47, to osition.

able passages, which cooperate with corresponding passages in the member 52, to constitute a labyrinth packing. A iy Wheel 53 of suitable size and construction is positioned upon the shaft 36 the hub of this fly Wheel contacting when in assembled position, with the member 52 to hold that member in proper position.

The cap 51 has attached thereto, preferably -as an integral part, a housing member to which is attached, as by means of bolts, a .cooperating housing member G1. The member 61 carries a packing housing 62 through which passes afstarting crank 63,

the inner end of which carries a suitable pin 64,- adapted to cooperate with a slot 65 in theclutch member 66. The clutch 66 is at- .tached to the shaft 36 by means of a nut. threaded on the end of said shaft, a suitable key and slot construction, 67, being provided to prevent rotation of the shaft and clutchl relative to each other. This clutch member also serves t i hold the Hy Wheel in position on the shaft. Suitable packing, 68, is positioned Within the packing housing 62,v a.

threaded gland 69, serving to keep'the packa ing material under such pressure as to prevent leakage. The spring 70 which abuts against a ring 71 and the gland 69 tends t Of course the housing dispensed with where the pressures in the engine cylinder are such.

that the labyrinth packing prevents leakage of the Working fluid.

The crank pin 41 passes through an opening 80 Within the extension 28 of the piston 27, a suitable ball-bearing 81 being provided to minimize the friction at this point during operation. The crank 39 passes through a suitable opening 82 in the cross bar 83, of the refrigerator member 84. Each of these constructions constitutes in effect what is known as a Scotch yoke. This refrigerator member as shown clearly in Figs. 3, 4 and 5 is cylindrical in form and so proportioned that it fits snugly Within the cylinder 20. lIt is composed of a material which is a good conductor of heat as compared with iron or steel, preferably aluminum or copper, and is provided With a plurality of passages 85, which serve to permit the ready passage of the gas Within the cylinder therethrough and at the same time to expose to this gas a greater surface. This refrigerator fits in heat transferring relation with the cylinder Wall. Because of its attachment to the crank pin.39 the refrigerator reciprocates Within the cylinder, during operation of the engine, the reciprocation bearl ying a definite time relation to the reciprocation of the piston. The openings'80 and 82 are so constructed that the outer ball races, of the ball-bearings cooperating with the crank pins 41 and 39, move along the Walls of the respective openings as the crank shaft rotates thus changing the reciprocating motion of the piston into rotating mot-ion of the crankshaft and the rotating motion of the crankshaft into reciprocating motion of the refrigerator. The refrigerator is cut away, as shown most clearly in Fig. 5, to receive the inner end of crank shaft 36 and the various partscooperating therewith.

Attached to the lower end of the refrigerator, by meansof the bolt 90 is a 'hollow cage 91, having its opposite ends perforated, to permit the ready passage therethrough of the gas Within the cylinder. `This cage, contains some material, such as finely spun glass wool` designated generally .by the numeral 92, whichv is of such character as to present a made suiiciently tight to y large surfacearea, and at the same time provide a construction whereby a plurality of openings or passages are provided so that the- 92 functions in two distinct Zones. The material in the zone A should be constructed to readily absorb the energy radiated by the heating body 23, constituting the principal heating element for directly heating the gases within the cylinder; and should thus also be so constructed that it is a good conductor of the radiant heat energy absorbed. The zone B functions as a regenerator.

The member 92, with the refrigerator, also constitutes the displacement menJoer the engine. As the displacement member moves toward or from the heated end 23 of the cylinder the gaswithin that cylinder is caused to move toward the cool end of the cylinder or back toward the hot end. As the displacement member moves toward the hot end the hot gas is forced to pass through the regenerator zone B where it gives up a part of its sensible heat to the spun glass, or similar material of which this zone is composed` The gas is then passed through the refrigerator 84 which absorbs some of its sensible heat and rejects that heat through the cylinder wall into the cooling water within the water jacket. The gas is thus cooled and caused to contract, and the piston 27 theref fore moves inwardly, under the action of the atmospheric pressure. The 'displacement member being 90 in advance of the piston has begun its outward movement as the piston begins to move inward. As this displacement member moves outwardly the cooled gas in the outer end of the cylinder is forced,

, first, through the regenerator zone B where it takes up some of the heat imparted to that regenerator on the previous stroke and then through the heating body, zone A, where its temperature is greatly increased. It then passes into the heated end of the cylinder where its temperature is somewhat further increased. But the zone A constitutes the principal heating body, the heat transferred to the gases directly from the body 23 being comparatively inconsiderable. This heat transfer into the gas causes its expansion and the piston is therefore forced outwardly. Rotation is thus imparted to the crankshaft 36, the ily wheel 53 serving to maintain that motion uniform.

Mounted upon the upper end of the cylin- 20, and surrounding the hollow end of the piston 27 and the sylphon bellows 30 is a hol-y low cap 95, which constitutes the cylinder of a compressor or pump. This cap is attached to the engine cylinder by suitable bolts, not shown, or by other conventional means` the i construction being such that this pump cylinder also holds the plate 25 in position and forms a continuation of the cylinder 20. The cylinder 95 has an inlet opening 96 to which is connected the supply pipe 97. Positioned within the inlet` opening 96 is an inlet valve comprising a seat member 98 with which cooperates a valve disc 99, normally held to its seat by means of a spring 100 mounted upon the bolt 101 which is threaded within the seat member 98. The cylinder 95 also has an outlet opening 102 therein, to which is connected the delivery pipe k103, which leads to any desired place of storage or use o f the material being pumped. As shown the apparatus is well adapted for use with a lgas producer, a part of the generated gas being burned to operate the engine, and the pump operated by the engine serving to furnish the suction for operating the producer and for pumping the gas to any desired place of use. Mounted withinthe outlet opening 102 is an outlet valve 104 similar in construction to the inlet valve described just above, but, of course, reversed in positioning. The opening in the hollow end of t-he piston 27 is closed by means of the plate 105. The piston 27 serves both as the power piston of the air engine and as the piston for the pump or compressor.

The combined engine and compressor is supported upon a base member 110, which may be of any suitable construction, the g upper end of this base member inelosing the end 23 of the cylinder1 and having a suitable lining 111, of fire brick, or analogous material, which ineloses the combustion chamber 112. A burner 113, at which any suitable fuel may be burned to generate the heat necessary for the operation of the engine, opens into the combustion chamber 112, the hot products of combustion passing olf through the outlets 114.

In Fig. 6 is shown a slightly modified form of construction in which the sylphon 30 is dispensed with, the piston 27 being of more conventional character, than that shown in Fig. 1, and of the proper shape and dimensions to snugly tit the inner wall of the extension 120, which is mounted upon the cylinder 20', and constitutes an extension thereofl The outer end of the extension 120 is provided with a cap 125, having two passages therein, adapted to receive respectively the inlet pipe 97 and the outlet pipe 103', each of which pipes has cooperating therewith a valve, such as is described above in connection with the form of invention shown in Figs. 1 and 2, the valve associated with the inlet pipe being designated generally by the numeral 99 while the valve associated with the outlet pipe is designated generally by the numeral 104. The pis; ton 120 is provided with any suitable means for preventing leakage, -the means shown being a plurality of grooves 121. Piston rings, of conventional design, may be used if desired but preferably the grooves shown are used since the friction as the result of the use of piston rings is excessive. The lower part of the piston is also provided with a key 122, which slides Iwithin a key way or groove 123 to prevent rotation of the piston within the cylinder. The head of the piston 120 is preferably detachable although this is not essential, being made in the form of a plate 130, which is suitably attached to the piston by means of bolts, screws, or the like, 131. The head of the piston is also provided with a depression 132 adapted to receive the lower end of the stem of the valve 97', so that clearance can thus be decreased. The mode of operation of this modification is substantially the same as that of the modification described above.

In Fig. 7 is shown still another modified form of the invention. In this particular form of apparatus the pump elements are dispensed with, and the apparatus constructed to function primarily as a motor or prime mover. Furthermore the engine is in inverted position, when compared with the forms shown in Figs. 1, 2 and 6. The apparatusl is substantially identical with that described above except that, because of it not being constructed to function as a pump, the cap which houses the inlet and outlet valves, to-

could, of course,

gether with these valves, is dispensed with, the inverted cylinder resting upon a base plate 150, supported upon suitable foundations by means of legs 151, this base plate being provided with a plurality of openings 152, through which the interior of this cylinder, below the piston 153 is connected to the atmosphere. 'But the mode of operation of the engine itself is -substantially identical with the mode of operation of the other forms.

In this form the crank for starting, with its enclosing housing, is also dispensed with. When it is desired to start the engine can be turned over by manipulation of the fly wheel 53. Also carried upon this shaft outside the fly wheel is a pulley 155 which serves to receive a drive belt 156 by means ot which the engine can be connected to any type of work device to be driven thereby.

As it is generally known, the cylinder of a hot air engine contains a gas, and as indicated by the name, this gas is usually atmospheric air. However any fixed gas be used in place of atmospheric air and throughout this specification and the claim`s thereto, the term hot air engine is intended to designate generally any engine o erating upon the same cycle as the described engine or the conventional hot air engine, even though the operating medium in the cylinder is not atmospheric air. In each type of hot air engine, illustrated and described herein, the oper ting medium is eferably maintained within the cylinder under such pressure conditions that at normal atmospheric temperatures the gas, or fluid, within the cylinder is under a pressure of several atmospheres. By increasing the normal pressure of the operating medium, within the cylinder, the power outputof the engine may be increased without any increase in its dimensions.

In addition to increasing the normal pressure of the operating medium to several atmospheres, more effective operation of the engine may be secured if there is also introduced into the cylinder, along with the fixed gas used, a material which is normally liquid at the temperatures and pressures which exist in the cooled end of the cylinder, and is normally in the vapor state under the temperatures and pressures existent in the heated end of the cylinder. All liquids will not function satisfactorily for this purpose, for the cycle of operation of the hot air engine is such that as the liquid vaporizes it is also subjected to greater pressure, which tends to increase its boiling point. With some liquids the boiling point rises so rapidly, under the increased pressures, that at the pressures attained' it will exceed the tcmperature existent in the hot end of the cylinder tending to vvaporize the liquid. It should be borne in mind, in this connection, that not only does the pressure increase because ot the expansion of the gas and the vaporization of th\e liquid, due to their receiving heat from the end of the cylinder, but the cycle of operation of the engine is such that at this time the piston is also moving inwardly thus tending to further increase the ressures. Of course there are a number of liquids that could be used, and no attempt is made lto enumerate them. However, a knowledge of the physical characteristics of the various available liquids will permit one sufliciently skilled to readily pick out one that is suitable. Further, this liquid should be not only such that it will vaporize despite the increase in pressures, but it should also be ot such character that it will be chemically inert in the presence of the fixed gas at all temperatures and pressures attained within the cylinder during operation of the engine. Hydrogen, as the fixed gas, and carbon tetrachloride, as the liquid, function very satisfactorily in this manner. And air and water will do ,very nicely when the pressures within the cylinder do not rise too high for the temperatures which are attained. The use of a liquid of this sort adds materially to the effectiveness of the engine for it permits of utilizing the latent heat of vaporization of the liquid, with the greater pressures due to the increased expansion attending such vaporization.

Either type of engine illustrated will function satisfactorily when air alone at normal pressures is the operating medium.

But each will function more effectively when the operating medium is a gas and a fluid, at greater than atmospheric pressures.

The type of construction shown lends itself to an extremely eective method of heat transfer from the burning fuel to the gases within the cylinder.

During operation the heating element or body 23 is heated to incandescence, this body being composed of a highly heat resistant material on this account. And as thus incandescent it radiates heat energy to the material of zone A `of element 91. This material is preferably fibrous in character, as illustrated, but it may be in any form which presents a large surface to the gases within the cylinder and divides those gases up into line streams to secure intimate contact between the gases and the surfaces of such material while also presenting such a construction that the heat energy radiated from the element 23, is readily absorbed. With this construction, the heat energy imparted to the body 23 is transferred to the zone A at a high rate by radiation, and is then rapidly transferred from this zone to the gases passing therethrough, in finely divided streams.

While the method herein described, and the forms of apparatus for carrying this method into effect, 'constitutes a preferred embodiment of thev invention, it is to be understood thatthe invention is not limited to this precise method and forms of apparatus, and that .changes may be made 1n either without de arting from the scope of the invention whlch is defined in the appended claims.

What is claimed is:

1. An engine of the character described, comprising, in combination, a cylinder; a

.piston therein; a hollow, perforated, displacement member containing a filamentous material, such as spun glass or the like, .within said cylinder, the construction being such that the surface of the displacement member exposed to the fluid Within the cylinder is increased, to cause said displacement member to function as a regenerator.

2. An engine of the characterv described, comprising, in combination, a cylinder; a piston therein; a displacement member in said cylinder; and a refrigerator, reciprocable Within the c linder.

3. An engine o the character described, comprising, in' combination, a cylinder, means for vcooling the wall of said cylinder, a piston in the cylinder, a displacement member reciprocable in the cylinder; and a refrigerator, fitting snugly Within the cylinder, lwith which the fluid within the cylinder' contacts as it is displaced upon reclprocation of the displacement member, the construction being such that heat 1s absorbed from the gas by the refrigerator member and transferred to the cylinder wall, from which it is removed by the cooling means.

' 4. A hot air engine comprising, in combination, a. cylinder; a piston therein; a displacement member in said cylinder; and a refrigerator carried by said displacement member.

5. An engine of the character described comprising, in combination, a cylinder; a piston therein; a displacement member in said cylinder, constructed to function as a regenerator; and a refrigerator, constructed to fit snugly within the cylinder, carried by said displacement member.

6. An engine of the character described, comprising, in combination, a cylinder; a piston therein operatively connected to a crank shaft; a displacement member, constructed to function as a regenerator, also operatively connected to said crank shaft; and a refrigerator carried by the displacement member; the displacement member and the refrigerator being each constructed to present a large heat absorbing surface to the fluid within the cylinder.

7. An engine of the character described, comprising, in combination, a cylinder; a piston and a displacement member therein; and a refrigerator, constructed of a. metal which is a good conductor of heat, also within said cylinder and in heat transferring relation with the Wall thereof.

8. A combined hot air engine and pump, comprising, in combination, an engine cylinder; a pump cylinder, forming a continuation thereof and having inlet and outlet valves therein; a plate, having a centrally arranged hole therein, interposed between the two cylinders; a piston lying partly within each of said cylinders and positioned Within the hole in the plate; and means associated with the piston and the said plate constructed to permit free movement of the piston within the hole in said plate but to seal the engine cylinder and pump cylinder from connection with each other.

9. A combined hot air engine and pump, comprising, in combination, an engine' cylinder; a pump cylinder forming a continuation thereof and having inlet and outlet lvalves therein; a plate, having a centrally connecting the displacement member to theci'ank shaft; a sylplion bellows surrounding the piston member and having one end thereof in gas tight connection with the plate, and the other end in gas tight connection with the pistonmember, the construction being such that the engine cylinder and pump cylinder are maintained out ofconnection with each other.

11.` A combined hot air engine and pump, comprising, in combination, an engine cylinder; having an openingy in the side wall thereof, a` displacement member in said .cylinder; a pump cylinder, forming a continuation of said engine cylinder; a plate, having a centrally arranged hole therein interposed between the two cylinders; a piston member positioned within the hole in the plate, the construction of the piston being such that it functions both'as a piston for the engine cylinder and as a piston for the pump cylinder; a crank shaft extending through the said opening4 in the side wall of the engine cylinder and terminating within the cylinder, a combined bearing and packing for said crank shaft, positioned within said opening, means for operatively connecting the piston member to the crank shaft; means for operatively connecting a displacement member to the crank shaft; a sylphon bellows surrounding the piston member and having one end thereof in vas tight connection with the piston mem er and the other end in gas tight connection with the cylinder structure, to seal the engine cylinder' and the pump cylinder froml connection with each other.

12. A combined hot air engine and pump, comprising, in combination, an engine cylinder, having an opening in the side wall thereof, a displacement member in said cylinder; a pump cylinder, forming a continuation of said engine cylinder; a. plate, having a centrally arranged hole therein, inter- .posed between the two cylinders; a piston member positioned within the hole in the plate, the construction of the piston being such that it functions both as a piston for the engine cylinder and as a piston for the pump cylinder; a crank shaft extending through said opening in the side wall of the engine cylinder and terminating within the cylinder, a combined bearing and packing member for the said crank shaft, the bearing being of the ball bearing type and the packing of the labyrinth type; means for operatively connecting the piston member to the crank shaft, and means for operatively connecting the displacement member to the crank shaft; and a sylphon bellows sui'- rounding the piston member and having one end thereof in gas tight connection with the plate, around the hole therein, and the other end in gas tight connection with the piston member.

13. An engine of the character described, comprising, in combination, a tightly sealed cylinder, a crank shaft associated therewith, a piston in said cylinder, connected to the crank shaft; a displacement member in said cylinder, also connected to the crank shaft; means for heatingone end of the cylinder, means for cooling the other end of the cylinder; and an operating medium in said cylinder comprising a xed gas and a material which will vaporize under the temperature and pressure existent in the heated end of the cylinder and will liquefy under the temperature and pressure existent in the cooled end of the cylinder, the fixed gas and the said other material being of such character that they are chemically inert with respect to each other at the temperatures and pressures to which theyl are subjected.

14. An engine of the character described comprising, in combination, a tightly sealed cylinder, a crank shaft associated therewith, a piston in the cylinder connected to the said crank shaft; a displacement Vmember lin the cylinder also connected to the crank shaft; means for heating one end of the cylinder, means for cooling the other end of the cylinder; and an operating medium in said cylinder consisting of hydrogen and carbontetrachloride.

15. An engine of the character described comprising, in combination, a tightly sealed cylinder; a piston in the cylinder; a displacement member also within the cylinder; and an operating mediumin the cylinder consisting of a fluid which at normally atmospheric temperatures is under a pressure of more than one atmosphere.

16. An engine of the character described, comprising, in combination, a tightly sealed cylinder; a piston in the cylinder; a displacement member also in the cylinder; and an operating medium in the cylinder which at normally atmospheric temperatures is under a pressure in excess of two atmospheres.

17. In an engine of the character described, a cylinder, a heating element within said cylinder, which is so constructed as to be a good absorber of radiant heat, and to also break up into fine streams, and to 'present a large surface to, a fluid passing thereover; a heating body' associated with said cylinder, and means for heating said heating body, the said heating element and heating body being so positioned relative to each other that heat energy may be radiated from the heating body to the heating element.

18. Apparatus of the character described comprising a closed cylinder, having an operating fluid therein, al piston Within said cylinder; a displacement member, Within said cylinder, having a plurality of passages therethrough, the said displacement member during operation of the device being reciprocated Within thc cylinder and throu the operating fluid, the said fluid belng 1- vided into fine streams as it passes through l5 the openings of said displacement member; a heating body associated with said cylinder, means for heating the said heating body; a heating element within said cylinder constructed to be a good absorber of zo In testimony whereof I heretoA alx my 25 4 signature.

HARRY F. SMITH. 

